jones



(No Model.)

L. D. JONES.

CHUCK.

310.374.743. Patented Dc. 13, 1337.

LOUIS D. JONES, OF CHICAGO, ILLINOIS, ASSIGNORv OF ONE-HALF TO VILLIAM E. SHAW, OF SAME PLACE.

CHUCK.

SPECIFICATION forming part-of Letters Patent No. 374.743, dated December 13, 1887.

Application filed July 22, 1887. Serial No. 245,010. (No model.)

To all whom it may concern:

Be it known that I, LoUIs D. JoNEs, of Chilcago,in the count-y of Cook and State of Illinois,

and delicate articles-such, for instance, as

watch-balance staffs, pinions, cylinders, Src.; and to this end the said invention consists in certain details o f construction and combinations of parts,to be hereinafter described, and pointed out particularly in the claims at the endlof this specification.

In the accompanying drawings, Figure 1 is a perspective-view of a chuck-center constructed in accordance with my invention, and Fig. 2 is a sectional view of the entire chuck. Fig. 3 is an end view. Fig. 4. is a view showing the invention applied to an ordinary wire split chuck.

Similar letters of reference in the several figures indicate the same parts.

A represents the body of the chuck-center,

split at the outer end, so as to form the three spring gripping-jaws B. These slots or slits between the spring-jaws are widened or enlarged into the opening C a short distance from the forward end of the chuck, which openings, meeting at the center, form quite a large open space at this'point. Extending back from this space to the rear end of the chuck-center is a round opening, in which worksa spring or pump centen7 D, held forward by the spiral spring a, which abuts against an enlargement of the said center D at the forward end and against a collar, b, surrounding the said center and screwing into the body Aat the rear end, as will be readily understood upon reference to Fig. 2. The/outside of my center is very similar to the ordinary center, save that the inclines E for forcing the jaws together are located somewhat erabl y do so.

farther from the end. rIhe openings O and set-screw c are loca-ted in this space.

.The operation of the chuck willA now be readily understood. The article to be operated upon-the cylinder of the balance-wheel of a watch, for instance, having a hub thereon-is inserted through one of the openings G and the end to be turned passed out between the gripping jaws, the pump center drawn back, and the other end of the cylinder inserted in the recess or socket f in its end. This has the eect of accurately centering the cylinder and holding it in line, at the same time pressing it forward imposition to be grasped by the jaws. When this has been accomplished, the screw c may be set up, thereby holding the pump-center rigidly in position, effectually preventing all liability of the cylinder held by the jaws being moved out of alignment or displaced in any way. Vhen the operations thus far described have been performed," the center grasping the article is inserted inthe lathe -spindle and thef jaws drawn together, as illustrated in Fig. 2, in which it will be seen the screw on the shaft of the hand wheel F engages the screw on the rear of the center A and draws it back, and the inclines E, abutting against the inclines G on the lathe-spindle H, force the gripping-jaws together. The screw h in the lathe-spindle H, engaging the slot a in the center A, prevents it turning with the hand-wheel.

Of course any form of mechanism may be employed for forcing the jaws together, as this featureforms no part of my present invention and is illustrated for convenience only.

It is obviousthat it is not essential that the pump-center be employed, although I pref- In Fig. 4. I have deemed it advisable to show the invention as applied to an ordinary chuck, such as is in universal use by watch-makers. V

Although in both forms of chuck I have shown the openings C formed in the slotssepmay be located at any point in the periphery of the center, even though they be cov--k ered by the spindle of the-lathe when it is inY place in the same. The advantages of my invention will be seen roof: i

at aglance. Various sizes of work may be operated upon with the same chuck,and work upon such articles as cylinders for Watch-balances may be held much more advantageously than with the ordinary chuck, the hub or en larged portion, being within the chuck, (see Fig. 2,) enabling the jaws to grasp the work very close to the point operated upon, greatly reducing theliability of bending or damaging the other portion, and entirely obviating the use of Wax to secure the article in place.

Having thus described my invention, what I claim as new isl. A chuck center having two or more Spring.grippingjaws andvprovided with an opening or openings at the side for the insertion of the work, substantially as described.

2. A chuck center having two or more spring gripping-jaws provided with an open- LOUIS D. JONES.

Witnesses:

WILLIAM S. MCCLORY, F. S. MoGLoRY. 

